An Atypical Case of Neurosyphilis in a Patient With HIV: A Case Report

Abstract

Epidemiological trends have demonstrated re-emergence of neurosyphilis in the twenty-first century. As prevalence rises in clinical practice, neurosyphilis must be considered in the differential diagnosis even if initial diagnostic workup is unrevealing, especially in patients with human immunodeficiency virus (HIV). Co-infection of neurosyphilis and HIV can result in atypical presentations. In this report, we discuss a challenging diagnosis of neurosyphilis in a man with HIV who presented with atypical imaging findings and initially negative cerebrospinal fluid (CSF) nontreponemal testing. Our patient underwent repeated CSF evaluation and a comprehensive diagnostic workup, including brain biopsy, to arrive at the appropriate diagnosis. He received antibiotic treatment with excellent outcome. We review typical imaging features of neurosyphilis and highlight other neurological diseases that may mimic these radiographic findings. We discuss CSF testing and interpretation in this high-risk patient population.

Keywords: HIV; central nervous system infections; headache; neurosyphilis.

Figure 1.

(A) T2-fluid-attenuated inversion recovery (FLAIR) axial image on presentation shows extensive left frontal vasogenic edema. (B) T1-post-contrast image from the same study shows enhancement in the anterior medial aspect of the left anterior cranial fossa. Left cranial nerve (CN) III and CN V enhancement not shown in this cross-section. (C) T2 FLAIR image 2 weeks after presentation with persistent left frontal vasogenic edema. (D) T1-post-contrast image 2 weeks after presentation shows ring-enhancement along the left cribriform plate and left CN III enhancement (green arrow). Left CN V enhancement not shown in this cross-section. (E) Diffusion-weighted imaging (DWI) image 2 weeks after presentation shows diffusion restriction (yellow arrow) along the left cribriform plate, corresponding to the area of enhancement on the T1-post-contrast study. (F) Apparent diffusion coefficient (ADC) image 2 weeks after presentation with low signal (red arrow) corresponding to the area of diffusion restriction on DWI. (G) T2-FLAIR image 1 year later shows near complete resolution of left frontal vasogenic edema. (H) T1-post-contrast image 1 year later shows minimal residual enhancement.